Well done. It's a solid little top-down shooter a la Hotline Miami or Police Stories. The graphics are detailed (though very zoomed out), the sound creates an atmosphere of utter dread, the controls are responsive.
Like those other games however it is also very, very difficult. Using one-hit kills is brutal because you only allow the player a single mistake. In the jam context it might be helpful to err on the side of leniency just to give the others an opportunity to see more of your game.